Supercharger for four-cycle gas fueled engines



May 1,1945. R. L. BOYER SUPERCHARGER FOR FOUR-CYCLE GAS Filed March 23, 1943 FUELED ENGINES Il ,4 l .2 //5'sssssssss a INVENToR. PH 13m/157?.4

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Patented May 1,194.45l

UNITED sm'rasv PATENT orrlcs surnncnancan Foa Form-CYCLE Gas FUELED ENGINES Ralph L. Boyer, Mount Vernon. Ohio, assignor to Cooper-Bessemer Corporation, Mount Ohio, a corporation of Ohio application Marsa 2s, 194s, serian No.' sans Vernon, l

i'claims, w1. 12s-izo) The supercharglng of Diesel engines and gasoline engines has become common practice but this has not been true in respect tofour cycle enginesy powered by gaseous fuels such asnatural gas, coke-oven gas or other by-product'gases, probably because of difilcultiesmet with in overcoming other objections ii supercharging by usual methods be attempted in engines of the last mentioned type.' The primary object 'of the `present inventionaccordingly is to provide Va superchargingl apparatus which will satisfy operating conditions ,gas fueled engine equipped with supercharglng apparatus capable of operating inaccordance y A `with, the present invention.

`l'g. 2 is a fragmentaryV crosslsectlonal view taken along the line 2--2 of Fig; l.

In carrying out the present invention aninl take manifold vi mair be used to which air under pressure is supplied by'a blower or turboblower indicated diagrammatically at 2, and drawing in air through an intake pipe' 3. Gaseous fuel under pressure will also be supplied from a supply pipe t leading to a manifold l. The manifolds l and' the gas valve is closed while the inlet valvestlll remains open, thus clearing the inlet passage of vcombustible mixture. after which the inlet valve closes. `Then when the inlet valve opens at the beginning of the ,next cycle there will be no residual combustible mixture whiclrmight make trouble in the event of-a backfire, and scavenging n may be secured by the initial stream of pure air .without-the wastage of gaseous fuel by passing out through the exhaust valve.

The illustrated apparatus will be described as applied to one of the cylinders l the cylinder head l of which is provided with an air conductlng passageway I (Fig. 2) connected' in usual manner to the intake manifold i, and a gaseous p fuel supply passageway Ill likewise connected to the manifold i.. The supply of air to the cylinder space, and also the supply of combustible mixture as hereinafter described, is controlled by a suitable inlet valve -II at the delivery end of the passagewayl. This valve is illustrated as of the poppet type having a stem l2, and urged toward closed position by a spring` I3, suitable mechanism being provided to hold the valve open at proper times, as typied byan oscillating arm. I4

, .having a studfli which engages the valve stem,

and a roller llyvhich engages a valve cam I1 on arotary shaft I8. I

' The gas valve I8 controls communication between the passageways I and I0, and as above mentioned is located only a short distance ahead of the m'aln valve Il, so that a mixture of gas and air is present only -in the delivery end of `passage- 5 will be connected to the respective engine cylinders 6 which may also be understood as connected in usual manner to anexhaust manifold 1.

In accordance with the present invention a main inlet valve controls the admission of a mixture of gas and air into the engine cylinders, the` gas entering into the mixture being kept separate i from the air untila pointl slightly in advance of the inlet'valve above mentioned, at' which point a gas valve is interposed so vtluit the supply of gas to mix with `the` air may be shut off when desired. Then the valves above mentioned are.

so controlled that the inlet valve opensahead of the gas valve, thus first supplyingto the engine cylinder pure air which may be used for scaveng- `ing purposes. Then the gas valve is opened so as to Supply to-the cylinder a combustible mixture of air and gas in suitable proportions; then way 8. This valve Il may also be of the poppet type having a stem 20, and being urged toward closed position by a spring 2l. `Appropriate operating mechanism will also be provided for proper timing of the valve, as typiiied by the os- 'cillating arm 22 pivoted about shaft 23 and havl ing a stud 2l to engage the valve stem, the arm 22 having a roller 25 engaging a cam 26 carried by a rotary timing shaft 2'I.A

As above mentioned the timingis such that I inlet valve il opens ahead of valve I8: This will admit pure air under pressure tothe cylinder,

and the stream of air accordingly may be used for scavenging purposes by opening valve i I while the exhaust valve ,(not shown) is still open. The exhaust valve is neither illustrated nor described in detail, since it may be assumed to be of any known or appropriate construction.

After scavenging is completed, the ses valve III 'win be open to admit m into the delivery ena or passageway I in admixture with the air, thus se- .curing Supercharging of the mixture, and after as previously described, there will be no residual combustible mixture in passageway 9 or in the intake manifold I, to cause trouble in the case of n backfire, as frequently happens in gas fueled four cycle engines. 'I'he eifects of backfire would be much more serious upon a combustible mixture under pressure, as would exist if residual gases from passageway I were permitted to remain in passageway 9 or manifold I. Also the above sequence of operation will render a stream of pure air accessible for scavenging purposes and prevent waste of fuel gas by passing into the exhaust manifold.

Preferably the pressure of the gas in passageway I0 is controlled according to the intake air pressure existing in manifold I. For this purpose a valve 28 indicated diagrammatically in Fig. 1 and controlled by a flexible diaphragm 29 subjected to the pressure of manifold I, is interposed between the gas supply pipe 4 and manifold 5 so as to regulate the pressure in manifold and passageways I Il according to the pressure existing in manifold I and passageways 9. In this way the gas-air ratio will be kept approximately constant, and governing of the engine may be secured by a throttle valve 30 in the air supply pipe 3 which reduces the Supercharging pressure when the engine is operating at lower loads.

While the invention has been disclosed as carried out by apparatus of the above described specic construction it should be understood that many changes may be made therein without departing from the invention in its broader aspects, within the scope of theappended claims.

I claim:

1. Supercharging apparatus for four cycle gas fueled engines having means for supplying air under pressure including an air conducting passageway leading to the cylinder, an inlet valve controlling communication between said passageway and the cylinder space, means for supplying gas under pressure including a gaseous fuel sup- Ply passageway leading to said air supply passageway near said inlet valve, a gas valve controlling communication between said passageways, and actuating means for said valves constructed and arranged to open said inlet valve before said gas valve to produce a flow of air under pressure through said first mentioned passageway and inlet valve, then open said gas valve to produce the flow of an air andl gas mixture under pressure through said inlet valve, and then close said gas valve before closing said inlet valve to provide a iiow-of air under pressure through said first mentioned passageway after the gas valve has closed and thereby discharge through the inlet valve, residual air and gas mixture from the space in the first mentioned passageway which lies between said valves.

2. Supercharging apparatus for multi-cylinder four cycle gas fueled engines, having an intake manifold with means for supplying air under pressure thereto, a gaseous fuel supply manifold having means for supplying gas under pressure thereto, air and gaseous fuel supply passageways for the respective cylinders connected respectively to said manifolds, inlet valve controlling communication between said air supply passageways and the respective cylinders, gas valves concontrolling communication between the respective air and fuel passageways, means constructed and arranged to open said inlet valves before and close the same after said gas valves, and means responsive to changes in pressure in said air manifold for varying the pressure in said fuel manifold.

3. Supercharging apparatus for multi-cylinder four cycle gas fueled engines, having an intake manifold with means for supplying air under pressure thereto, a gaseous fuel supply manifold having means for supplying gas under pressure thereto, air and gaseous fuel supply passageways for the respective cylinders connected respectively to said manifolds, inlet valves controlling communication between said air supply passageways and the respective cylinders, gas ,valves controlling communication between the respective air and fuel passageways, means constructed and arranged to open said inlet valves before and close the same after said gas valve, means responsive to changes in pressure in said air manifold for varying the pressure in said fuel manifold, and a throttle valve for regulating the pressure of the air supplied to said air intake manifold.

4. Supercharging apparatus for four cycle gas fueled engines having means for supplying air under pressure including an air conducting passageway leading to the cylinder, an inlet valve controlling communication between said passageway and the cylinder space, means for supplying gas under pressure including a gaseous fuel supply passageway leading to said air supply passageway near said inlet valve, a gas valve controlling communication between said `passageways, and actuating means for said valves constructed and arranged to open said inlet valve before and close the same after said gas valve, means being provided to regulate the pressure in said fuel passageway in proportion to the pressure in said air passageway.

RALPH L. BOYER. 

